Estimation of age at death from second metacarpals.

This study examined the estimation of age at death from the second metacarpal in 227 individuals aged 30-98 years. Variables ascertained from each bone were: cortical thickness and microdensitometric cortical bone density measured on radiographs of the bone and total osteon count and density recorded on microradiographs of the complete cross section at its midshaft. Based on the latter two variables, two age groups were formed; a middle age group representing those individuals aged 30-65 years, and an older group aged 65+. Stepwise regression analysis of the four variables produced a series of regression equations for age estimation for the middle, old and combined age groups for each sex and sexes combined. Sex-specific equations provided better results than nonspecific ones, especially in females. Total osteon density and combined cortical thickness were found to be the most useful estimators in the middle and the old age group, respectively. The standard error of estimate was 6.71 and 6.90 years in each age group for the sexes combined. In the combined age group, age could be estimated accurately from total osteon count, cortical thickness and MD cortical bone density with the standard error of estimate of 11.10 years. The relative error of estimate ranged within +/- 30% in almost all individuals aged above 60 years.     

Caries and periodontal disease of the elderly in Pomerania, Germany: results of the Study of Health in Pomerania

Objective: The aim of this study was to describe the oral health status of older adults living in north‐eastern Germany. Materials and Methods: Representative samples of adults aged 60 years or older were examined as part of Study of the Health in Pomerania, a cross‐sectional, population‐based study. Data on 1446 subjects aged 60–79 years were evaluated for coronal caries using the decayed/missing/filled teeth (DMFT) index, root caries using the root caries index (RCI), calculus, plaque, bleeding on probing, pocket depth and attachment loss. Results: The prevalence of edentulousness varied from 16% in the 60–65‐year‐old group to 30% in the 75–79‐year‐old group, whereas the median number of remaining natural teeth per subject varied from 14 in the youngest age group (60–65 years) to one in the oldest (75–79 years). Among subjects aged 60–69 years, a quarter (26%) of the teeth examined had coronal restoration against 17% in the oldest age group (70–79 years). Coronal caries was found in 2% of the teeth in both age groups. Among teeth with gingival recession, 6% had fillings on root surfaces and 2% had root caries, irrespective of age. In all, 11% of the subjects had at least one untreated coronal lesion and 27% had at least one untreated root caries lesion. Plaque score, calculus score and bleeding on probing were higher in the oldest age group (70–79 years). The prevalence of periodontal disease expressed as the presence of at least one periodontal pocket of 4 mm and more, was higher in men and among the younger subjects (men aged 60–69 years: 85% vs. 71% in 70–79‐year‐old men; women aged 60–69 years: 71% vs. 62% in 70–79‐year‐olds). The prevalence of attachment loss of 3 mm or more followed a similar pattern. Conclusions: It seems therefore that in this population, the major oral health concern is related to caries and the small number of teeth retained among the dentate subjects.     

Projection of older Australians with a history of midlife obesity and overweight 2010–2050

Objective: This study projects midlife obesity status in future older Australians. Design and Methods: Cross‐sectional prevalence of being obese or overweight by broad age groups was interpolated to obtain single‐year‐age data. These estimates were then used to derive prevalence of normal weight and underweight. Data by birth year and year of observation of persons aged 30–70 years were used to construct prediction equations. Results: Results show that older people with a history of midlife obesity is projected to rise substantially in the future. For people aged 65 years, midlife obesity was estimated at 22% in 2010 and is projected to increase to 43% for males and 37% for females in 2050. Conclusion: While the proportion of individuals with midlife normal weight is projected to decline substantially, prevalence of midlife overweight remains almost stable. The number of persons aged 65 years and over having a history of midlife obesity is projected to increase nearly six‐fold from less than 500,000 persons in 2010 to 2.8 million in 2050. In comparison, between 2010 and 2050, Australia's older population aged 65 years and over is projected to increase by only 2.5‐fold. Growing obesity prevalence in the Australian population translates into a large increase in older people with a history of midlife obesity, with major implications for the future burden of disease in older persons.     

Patterns of femoral bone remodeling dynamics in a medieval Nubian population

The relationship between age, sex and histomorphometry in femoral cortical bone was examined in a skeletal population of late Medieval antiquity (AD 1250–1450) from Kulubnarti, in Sudanese Nubia. These skeletal remains are naturally mummified and in an excellent state of preservation. The study sample consisted of femoral cross sections from 24 females and 19 males ranging in age from 20 to 50+ years. Femoral cross sections were examined using an image analysis system. Numbers of secondary osteons and osteon fragments were counted, osteon area and Haversian canal area were measured, and several variables were calculated to assess differences between sexes and among age groups in bone remodeling variables. The results indicate significant differences between the sexes in osteon number and size. Males had significantly more intact osteons than females, whereas females had significantly larger osteons than males. Haversian canal dimensions were not statistically significant between the sexes. Sex differences in activity patterns in which males were involved in more physically strenuous tasks may have contributed to differences in remodeling variables. Interpopulational comparisons suggest that mechanical strain affects the microstructural features examined in this study. In particular, small Haversian canals in some archaeological skeletal populations are associated with higher bone volume, which may result from high levels of mechanical strain. Am J Phys Anthropol 104:133–146, 1997. © 1997 Wiley-Liss, Inc.     

Ambulant 24‐h glucose rhythms mark calendar and biological age in apparently healthy individuals

Glucose metabolism marks health and disease and is causally inferred in the aging process. Ambulant continuous glucose monitoring provides 24‐h glucose rhythms under daily life conditions. We aimed to describe ambulant 24‐h glucose rhythms measured under daily life condition in relation to calendar and biological age in apparently healthy individuals. In the general population and families with propensity for longevity, we studied parameters from 24‐h glucose rhythms; glucose levels; and its variability, obtained by continuous glucose monitoring. Participants were 21 young (aged 22–37 years), 37 middle‐aged (aged 44–72 years) individuals from the general population, and 26 middle‐aged (aged 52–74 years) individuals with propensity for longevity. All were free of diabetes. Compared with young individuals, middle‐aged individuals from the general population had higher mean glucose levels (5.3 vs. 4.7 mmol L^?1, P < 0.001), both diurnally (P < 0.001) and nocturnally (P = 0.002). Glucose variability was higher in the middle‐aged compared with the young (standard deviation 0.70 vs. 0.57 mmol L^?1, P = 0.025). Compared with middle‐aged individuals from the general population, middle‐aged individuals with propensity for longevity had lower overall mean glucose levels (5.2 vs. 5.4 mmol L^?1, P = 0.047), which were more different nocturnally (4.8 vs. 5.2 mmol L^?1, P = 0.003) than diurnally (5.3 vs. 5.5 mmol L^?1, P = 0.14). There were no differences in glucose variability between these groups. Results were independent of body mass index. Among individuals without diabetes, we observed significantly different 24‐h glucose rhythms depending on calendar and biological age.     

Basics in paleodemography: a comparison of age indicators applied to the early medieval skeletal sample of Lauchheim

Recent advances in the methods of skeletal age estimation have rekindled interest in their applicability to paleodemography. The current study contributes to the discussion by applying several long established as well as recently developed or refined aging methods to a subsample of 121 adult skeletons from the early medieval cemetery of Lauchheim. The skeletal remains were analyzed by 13 independent observers using a variety of aging techniques (complex method and other multimethod approaches, Transition Analysis, cranial suture closure, auricular surface method, osteon density method, tooth root translucency measurement, and tooth cementum annulation counting). The age ranges and mean age estimations were compared and results indicate that all methods showed smaller age ranges for the younger individuals, but broader age ranges for the older age groups.     

CO2 exchange and evapotranspiration across dryland ecosystems of southwestern North America

Global‐scale studies suggest that dryland ecosystems dominate an increasing trend in the magnitude and interannual variability of the land CO₂ sink. However, such analyses are poorly constrained by measured CO₂ exchange in drylands. Here we address this observation gap with eddy covariance data from 25 sites in the water‐limited Southwest region of North America with observed ranges in annual precipitation of 100–1000 mm, annual temperatures of 2–25°C, and records of 3–10 years (150 site‐years in total). Annual fluxes were integrated using site‐specific ecohydrologic years to group precipitation with resulting ecosystem exchanges. We found a wide range of carbon sink/source function, with mean annual net ecosystem production (NEP) varying from ‐350 to +330 gCm^?2 across sites with diverse vegetation types, contrasting with the more constant sink typically measured in mesic ecosystems. In this region, only forest‐dominated sites were consistent carbon sinks. Interannual variability of NEP, gross ecosystem production (GEP), and ecosystem respiration (R_eco) was larger than for mesic regions, and half the sites switched between functioning as C sinks/C sources in wet/dry years. The sites demonstrated coherent responses of GEP and NEP to anomalies in annual evapotranspiration (ET), used here as a proxy for annually available water after hydrologic losses. Notably, GEP and R_eco were negatively related to temperature, both interannually within site and spatially across sites, in contrast to positive temperature effects commonly reported for mesic ecosystems. Models based on MODIS satellite observations matched the cross‐site spatial pattern in mean annual GEP but consistently underestimated mean annual ET by ~50%. Importantly, the MODIS‐based models captured only 20–30% of interannual variation magnitude. These results suggest the contribution of this dryland region to variability of regional to global CO₂ exchange may be up to 3–5 times larger than current estimates.     

Cross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese Macaques

Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross‐sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non‐provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross‐sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1–4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter‐group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4–11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross‐sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4–5 mo, but were significantly lower in Ohirayama individuals aged 7–8 and 9–11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter‐group differences in coo call features form approximately 6–7 mo after birth as a result of vocal plasticity.     

Congruent phylogeographic patterns in a young radiation of live‐bearing marine snakes: Pleistocene vicariance and the conservation implications of cryptic genetic diversity

Aim

To investigate phylogeographic patterns among and within co‐occurring sea snake species from Australia's endemic viviparous Aipysurus lineage, which includes critically endangered species, and evaluate the conservation implications of geographically structured patterns of genetic divergence and diversity.

Location

Australia's tropical shallow water marine environments spanning four regions: Great Barrier Reef (GBR), Gulf of Carpentaria (GoC), Timor Sea (TS) and coastal WA (WAC).

Methods

Samples from >550 snakes representing all nine nominal Aipysurus group species were obtained from throughout their known Australian ranges. Coalescent phylogenetic analyses and Bayesian molecular dating of mitochondrial DNA, combined with Bayesian and traditional population genetic analyses of 11 microsatellite loci, were used to evaluate genetic divergence and diversity.

Results

Mitochondrial DNA revealed highly congruent phylogeographic breaks among co‐occurring species, largely supported by nuclear microsatellites. For each species, each region was characterized by a unique suite of haplotypes (phylogroups). Divergences between the TS, GoC and/or GBR were invariably shallow and dated as occurring 50,000–130,000 years ago, coinciding with the cyclic Pleistocene emergence of the Torres Strait land bridge. By contrast, sea snakes from coastal WA were consistently highly divergent from other regions and dated as diverging 178,000–526,000 years ago, which was not associated with any known vicariant events.

Main Conclusions

Previously unappreciated highly divergent sea snake lineages in coastal WA potentially represent cryptic species, highlighting this region as a high‐priority area for conservation. The cyclic emergence of the Torres Strait land bridge is consisted with observed divergences between the TS, GoC and/or GBR; however, processes involved in the earlier divergences involving the WAC remain to be determined. The observed strong population genetic structures (as surrogates for dispersal) indicate that sea snakes have limited potential to reverse population declines via replenishment from other sources over time frames relevant to conservation.

     

A mitochondrial revelation of early human migrations to the Tibetan Plateau before and after the last glacial maximum

As the highest plateau surrounded by towering mountain ranges, the Tibetan Plateau was once considered to be one of the last populated areas of modern humans. However, this view has been tremendously changed by archeological, linguistic, and genetic findings in the past 60 years. Nevertheless, the timing and routes of entry of modern humans into the Tibetan Plateau is still unclear. To make these problems clear, we carried out high‐resolution mitochondrial‐DNA (mtDNA) analyses on 562 Tibeto‐Burman inhabitants from nine different regions across the plateau. By examining the mtDNA haplogroup distributions and their principal components, we demonstrated that maternal diversity on the plateau reflects mostly a northern East Asian ancestry. Furthermore, phylogeographic analysis of plateau‐specific sublineages based on 31 complete mtDNA sequences revealed two primary components: pre‐last glacial maximum (LGM) inhabitants and post‐LGM immigrants. Also, the analysis of one major pre‐LGM sublineage A10 showed a strong signal of post‐LGM population expansion (about 15,000 years ago) and greater diversity in the southern part of the Tibetan Plateau, indicating the southern plateau as a refuge place when climate dramatically changed during LGM. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Setup of a bone aging experimental model in the rabbit comparing changes in cortical and trabecular bone: Morphological and morphometric study in the femur

Bone aging was studied in an experimental model (rabbit femur) in three populations aged 0.5, 1.5, and 7.5 years. Cortical bone histology was compared with a data set from a 1.5‐month‐old population of an earlier published paper. From 0.5‐year‐old onward, the mean femur length did not increase further. Thereafter, the mean marrow area increased and the cortical area decreased significantly with aging. This was associated with a structural pattern transformation from plexiform to laminar and then Haversian‐like type. The distal meta‐epiphysis bone trabecular density of the oldest populations also was significantly lower in specific regions of interest (ROI). Percentage sealed primary vascular canals in laminar bone significantly increased with aging without variation of percentage sealed secondary osteons. Remodeling rate reflected by the density of cutting cones did not significantly change among the age populations. These data suggest that laminar bone vascular pattern is more functional in the fast diaphyseal expansion but not much streamlined with the renewal of blood flow during secondary remodeling. Bone aging was characterized by: 1) secondary remodeling subendosteally; 2) increment of sealed primary vascular canals number; 3) increased calcium content of the cortex; 4) cortical and trabecular bone mass loss in specific ROIs. Taken together, the present data may give a morphological and morphometric basis to perform comparative studies on experimental models of osteoporosis in the rabbit. J. Morphol. 276:733–747, 2015. © 2015 Wiley Periodicals, Inc.     

Evidence of non-early ultrastructural regionalization in the neural epithelium of the chick by stereological methods

Cell populations of the anterior, medial and posterior regions of the neural epithelium of chick embryo were analyzed by ultrastructural morphometrical and stereological methods. No morphological subcellular differences appear to occur between the cells of these distinct areas, demonstrable by morphometrical and stereological conventional methods. The homogeneity of this cell population in each stage during neurulation is discussed in relation to the induction process.     

Assessing the oral health of an ageing population: methods, challenges and predictors of survey participation

doi: 10.1111/j.1741‐2358.2011.00540.x Assessing the oral health of an ageing population: methods, challenges and predictors of survey participation Objectives: To examine predictors of participation and to describe the methodological considerations of conducting a two‐stage population‐based oral health survey. Methods: An observational, cross‐sectional survey (telephone interview and clinical oral examination) of community‐dwelling adults aged 45–64 and ≥65 living in Nova Scotia, Canada was conducted. Results: The survey response rate was 21% for the interview and 13.5% for the examination. A total of 1141 participants completed one or both components of the survey. Both age groups had higher levels of education than the target population; the age 45–64 sample also had a higher proportion of females and lower levels of employment than the target population. Completers (participants who completed interview and examination) were compared with partial completers (who completed only the interview), and stepwise logistic regression was performed to examine predictors of completion. Identified predictors were as follows: not working, post‐secondary education and frequent dental visits. Conclusion: Recruitment, communications and logistics present challenges in conducting a province‐wide survey. Identification of employment, education and dental visit frequency as predictors of survey participation provide insight into possible non‐response bias and suggest potential for underestimation of oral disease prevalence in this and similar surveys. This potential must be considered in analysis and in future recruitment strategies.     

Estimating age of mature adults from the degeneration of the sternal end of the clavicle

The sternal end of the clavicle has been illustrated to be useful in aging young adults, however, no studies have investigated what age‐related changes occur to the sternal end post epiphyseal fusion. In this study, three morphological features (i.e., surface topography, porosity, and osteophyte formation) were examined and scored using 564 clavicles of individuals of European ancestry (n = 318 males; n = 246 females), with known ages of 40+ years, from four documented skeletal collections: Hamann‐Todd, Pretoria, St. Bride's, and Coimbra. An ordinal scoring method was developed for each of the three traits. Surface topography showed the strongest correlation with age, and composite scores (formed by summing the three separate trait scores) indicated progressive degeneration of the surface with increasing chronological age. Linear regression analyses were performed on the trait scores to produce pooled‐sample age estimation equations. Blind tests of the composite score method and regression formulae on 56 individuals, aged 40+ years, from Christ Church Spitalfields, suggest accuracies of 96.4% for both methods. These preliminary results display the first evidence of the utility of the sternal end of the clavicle in aging older adult individuals. However, in the current format, these criteria should only be applied to individuals already identified as over 40 years in order to refine the age ranges used for advanced age. These findings do suggest the sternal end of the clavicle has potential to aid age estimates beyond the traditional “mature adult” age category (i.e., 46+ years), and provides several suggestions for future research. Am J Phys Anthropol 156:203–214, 2015. © 2014 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.     

Osteon remodeling dynamics in the Cayo Santiago Macaca mulatta: The effect of matriline

At the microstructural level, bones remodel throughout life. This process is recorded in bone cortex as osteons. A more comprehensive understanding of the interaction between genetic regulation and environmental factors in osteon remodeling will increase the value of this skeletal record and enable more accurate reconstruction of individual life histories. The purpose of this study was to examine the contribution of maternal lineage to normal age and sex variation in osteon remodeling dynamics in Macaca mulatta. Femoral cross sections from 57 Cayo Santiago-derived rhesus macaques representing five matrilines were examined to evaluate the effect of genetic relatedness on osteon remodeling dynamics. Analysis of variance revealed an effect of maternal lineage on osteon area and Haversian canal area. The other variables did not differ significantly among matrilines. Analysis of covariance revealed no significant interactions among age, sex, and matriline for any of the microstructural variables.     

用显微镜确定骨龄的初步研究

作者对在广西地区收集的年龄从5岁至86岁的35副完整骨骼的右股骨中点横断磨片的骨单位数、骨间板数、非哈弗氏管数及外环骨板平均相对厚度进行了观测和计算。这些指标与年龄之间均存在非常显著的相关,并建立了相应的回归方程。这些回归方程的估计年龄与实际年龄的误差在±5岁以内的,达80％左右;在±10岁以内的,达90％左右。与用Kerley法所作的对比检验表明,本文方法较适用于国人材料。     

Detection of silent cells,synchronization and modulatory activity in developing cellular networks

Developing networks in the immature nervous system and in cellular cultures are characterized by waves of synchronous activity in restricted clusters of cells. Synchronized activity in immature networks is proposed to regulate many different developmental processes, from neuron growth and cell migration, to the refinement of synapses, topographic maps, and the mature composition of ion channels. These emergent activity patterns are not present in all cells simultaneously within the network and more immature “silent” cells, potentially correlated with the presence of silent synapses, are prominent in different networks during early developmental periods. Many current network analyses for detection of synchronous cellular activity utilize activity‐based pixel correlations to identify cellular‐based regions of interest (ROIs) and coincident cell activity. However, using activity‐based correlations, these methods first underestimate or ignore the inactive silent cells within the developing network and second, are difficult to apply within cell‐dense regions commonly found in developing brain networks. In addition, previous methods may ignore ROIs within a network that shows transient activity patterns comprising both inactive and active periods. We developed analysis software to semi‐automatically detect cells within developing neuronal networks that were imaged using calcium‐sensitive reporter dyes. Using an iterative threshold, modulation of activity was tracked within individual cells across the network. The distribution pattern of both inactive and active, including synchronous cells, could be determined based on distance measures to neighboring cells and according to different anatomical layers. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 357–374, 2016     

Isotopic evidence of dietary variations and weaning practices in the Gaya cemetery at Yeanri,Gimhae, South Korea

Stable carbon and nitrogen isotope analyses were conducted to investigate dietary variation in human skeletons (n = 109) from the Gaya cemetery at Yeanri located near Gimhae City, South Korea. The cemetery contained three distinct grave types dating to 4th–7th century AD. The main purposes of this research were to reconstruct palaeodiet in the Gaya population and to explore correlations between stable isotope compositions and burial types, inferred age, and sex of these individuals. The isotopic data indicate that the people at Yeanri consumed a predominantly C₃‐based terrestrial diet supplemented with freshwater and/or marine resources. The comparison of isotopic results reveals significant differences in δ¹³C values among three adult burial types (wood‐cist coffin: ?18.5 ± 0.5‰, stone‐cist coffin: ?18.1 ± 0.6‰, mausoleum: ?17.8 ± 0.9‰). Males in wood‐cist and stone‐cist coffins have relatively more elevated mean δ¹³C and δ¹⁵N values than females. The isotopic ratios from the two adult age groups (21–40 years and 40–60 years) indicate that there was no significant dietary change in individuals with age. The isotope data from the infants and children suggest the weaning was a gradual process that was completed between 3 and 4 years of age in the Gaya population. This evidence indicates that the dietary variations within the cemetery reflect social status, sex, and childhood consumption patterns. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

The African savannah elephant population in Kidepo Valley National Park, Uganda: changes in size and structure from 1967 to 2000

The age and sex structure of the elephant population in Kidepo Valley National Park were studied using recognition files. Moreover, population trends were reviewed using past studies. From 1967 to 2000, the elephant population varied between 200 and 500 individuals. Of the minimum number of 374 elephants found to use the Park, 352 were individually identified. Seventy‐nine per cent of these were recorded in 29 families ranging from three to 22 animals with a mean group size of ten. Young animals dominated the population (45% aged 0–9.9 years), while 11% were 10–14.9 years of age and only 18% over 25 years of age. Overall, males constituted 45% of the population, but only 32% of the individuals in the 10–14.9‐year age class were males. Individuals ≥15 years of age displayed a skewed sex ratio of 1 : 1.4 in favour of females. The extent of skew was greatest among mature animals (≥25 years of age), which had four times as many females as males. The skewed age structure in the year 2000 caused by poaching and drought, led to a significant difference between the age distribution in 1970 and 2000. Recent counts suggest that the Kidepo elephant population may be increasing.